A number of dispensers exist in the prior art for dispensing paper toweling and the like. Some of these dispensers are of the "center-pull" type wherein a web of toweling or other sheet material is pulled from the center of a coreless roll through a nozzle or other restricted element forming a restricted passageway. Assuming that the individual sheets of toweling or the like are connected by perforated lines, as is common, the nozzle or other restrictor element will resist pulling of the sheet material by the user, thus breaking an individual sheet from the remaining web along the perforated lien interconnecting same.
It is quite common to utilize center-pull nozzles which have a cone-like or funnel-shaped configuration. For example, U.S. Pat. No. 4,905,868, issued Mar. 6, 1990, discloses a paper towel dispenser employing a conical funnel having an exit hole larger than the entrance hole thereof which provides an exit for paper towels being dispensed. The entrance opening and exit opening of the conical funnel are dimensioned such that a first paper towel will separate from a following paper towel along the perforation boundary therebetween when a leading portion of the following paper towel exits from the exit opening in the funnel.
The cone or funnel-like nozzle disclosed in U.S. Pat. No. 4,905,868 has a characteristic which is believed to be typical of center-pull dispenser nozzles of the cone or funnel type. Namely, the inner and outer walls of the nozzle terminate at a common plane at the bottom of the nozzle, creating a sharp edge where the nozzle exit opening is defined by the nozzle wall. This results in fairly rapid wear of the nozzle at the exit opening and an increase in the size of the exit opening. A change in the dimensions of the nozzle exit opening can result in improper operation of the dispenser. Most commonly, this manifests itself in the inability of the device to provide a clean or complete separation between the lead sheet and that following.
The following patents were also located during a search directed to this invention: U.S. Pat. No. 4,534,491, issued Aug. 13, 1985, U.S. Pat. No. 4,651,895, issued Mar. 24, 1987, U.S. Pat. No. 2,340,090, issued Jan. 25, 1944, U.S. Pat. No. 1,649,273, issued Nov. 15, 1927, and U.S. Pat. No. 4,262,816, issued Apr. 21, 1981. The patents relate to various approaches for dispensing towels and other sheets from a supply thereof by pulling the sheets through a restricted opening to detach one sheet from another.